Organic light emitting diode display and driving method thereof
First Claim
1. An organic light emitting diode display, comprising:
- a light emitting cell connected between a high-level voltage source and a first node;
a driving transistor connected between the first node and a ground voltage source to control a current flow in the light emitting cell, by using a voltage applied to a gate terminal of the driving transistor;
a data driving circuit configured to apply a data voltage of first polarity to the gate terminal of the driving transistor to shift a threshold voltage of the driving transistor from a reference value to the voltage of first polarity; and
a compensation circuit configured to supply a compensation voltage of second polarity, which is different from the first polarity, to the gate terminal of the driving transistor to shift the threshold voltage of the driving transistor from the voltage of first polarity to the voltage of second polarity, whereinthe compensation circuit then supplies a constant current to the gate terminal of the driving transistor to restore the threshold voltage of the driving transistor to the reference value.
2 Assignments
0 Petitions
Accused Products
Abstract
An organic light emitting diode display compensates for a threshold voltage of a thin-film driving transistor to improve display quality. The display includes a light emitting cell connected between a high-level voltage source and a first node. A driving transistor is connected between the first node and a ground voltage source to control a current, which flows in the light emitting cell, by using a voltage applied to a gate terminal of the driving transistor. A data driving circuit applies a data voltage of first polarity to the gate terminal of the driving transistor to shift a threshold voltage of the driving transistor from a reference value to the voltage of first polarity. A compensation circuit supplies a compensation voltage of second polarity to the gate terminal of the driving transistor to shift the threshold voltage of the driving transistor from the voltage of first polarity to the voltage of second polarity, and then supplies a constant current to the gate terminal of the driving transistor to restore the threshold voltage of the driving transistor to the reference value.
-
Citations
11 Claims
-
1. An organic light emitting diode display, comprising:
-
a light emitting cell connected between a high-level voltage source and a first node; a driving transistor connected between the first node and a ground voltage source to control a current flow in the light emitting cell, by using a voltage applied to a gate terminal of the driving transistor; a data driving circuit configured to apply a data voltage of first polarity to the gate terminal of the driving transistor to shift a threshold voltage of the driving transistor from a reference value to the voltage of first polarity; and a compensation circuit configured to supply a compensation voltage of second polarity, which is different from the first polarity, to the gate terminal of the driving transistor to shift the threshold voltage of the driving transistor from the voltage of first polarity to the voltage of second polarity, wherein the compensation circuit then supplies a constant current to the gate terminal of the driving transistor to restore the threshold voltage of the driving transistor to the reference value. - View Dependent Claims (2, 3, 4, 5, 6, 7)
-
-
8. A method of driving an organic light emitting diode display, the display including a light emitting cell connected between a high-level voltage source and a first node, and a driving transistor connected between the first node and a ground voltage source to control current flow in the light emitting cell by using a voltage applied to a gate terminal of the driving transistor, the method comprising:
-
applying a data voltage of first polarity to the gate terminal of the driving transistor to shift a threshold voltage of the driving transistor from a reference value to the voltage of first polarity; shifting the threshold voltage of the driving transistor from the voltage of first polarity to a voltage of second polarity by supplying a compensation voltage of second polarity different from the first polarity, to the gate terminal of the driving transistor; and restoring the threshold voltage of the driving transistor to the reference value by supplying a constant current to the gate terminal of the driving transistor from a constant current source. - View Dependent Claims (9, 10)
-
-
11. An organic light emitting diode display, comprising:
-
a light emitting cell connected between a high-level voltage source and a first node; a driving transistor connected between the first node and a ground voltage source to control a current flow at the light emitting cell, using a voltage applied to a gate terminal of the driving transistor; a data driving circuit configured to apply a data voltage to the gate terminal of the driving transistor to increase a threshold voltage of the driving transistor to a value greater than a reference value; a compensation circuit configured to supply a compensation voltage, which is different from the data voltage, to the gate terminal of the driving transistor to reduce the threshold voltage of the driving transistor to a value less than the reference value; and the compensation circuit configured to supply a constant current to the gate terminal of the driving transistor to restore the threshold voltage of the driving transistor to the reference value.
-
Specification